1. Field of the Invention
This invention relates to tasteless and practically water insoluble salts, useful in formulating pharmaceutical suspensions, of physiologically active substituted phenylalkanoic acids. More particularly, this invention relates to the mono- and di-basic aluminum salts of 2-(3-phenoxyphenyl)-and 2-(3-phenylthiophenyl)-alkanoic acids. Said salts, being tasteless and practically water insoluble at pH's of from about 6 to 9, and which revert to the physiologically active phenylalkanoic acid moieties at the pH of the stomach, are uniquely adapted for use in pharmaceutical suspension.
2. Description of the Prior Art
Physiologically active substituted phenylalkanoic acids are taught and claimed in U.S. Pat. No. 3,600,437. The substituted phenylalkanoic acids there taught are particularly active as antiinflammatory agents.
Antiinflammatory agents are almost uniformly prescribed in most clinical cases of arthritis. And, generally, arthritis is an affliction of the older segment of the population. In those persons 70 and older, almost every one has an active case of clinically diagnosed arthritis. Solid pharmaceutical dosage forms for oral administration, such as capsules, granules, pills, powders, and tablets can be readily prepared directly from the more soluble salts of substituted phenylalkanoic acids. However, many older persons prefer liquid medical preparations to the solid forms, because such are easier to swallow.
Most salts of substituted phenylalkanoic acids having antiinflammatory activity are difficult to formulate into pharmaceutically acceptable liquid dosage form because of a small amount of water solubility which makes the taste hard to mask.
Accordingly it is an object of this invention to provide water insoluble salts of the substituted phenylalkanoic acids.
It is a further object of this invention to provide water insoluble salts of the substituted phenylalkanoic acids which are biologically available when ingested into the stomach of a mammal.
It is yet another object of this invention to provide biologically available water insoluble salts of the substituted phenylalkanoic acids which are chemically stable and inert towards the commonly used adjuvants employed in pharmaceutical suspension.
Still another object of the instant invention is to provide chemically stable, inert, water insoluble, and biologically available salts of the substituted phenylalkanoic acids which are tasteless.
A further object of this invention is to provide chemically and physically stable pharmaceutical suspensions of the substituted phenylalkanoic acids.